Gödel did something very clever. He found a solution of Einstein’s field equations in which the world lines circled back on themselves. This means that if you were traveling along a world line you would eventually encounter yourself as a baby. Suppose you kill yourself as a baby. Would you still be alive? It would be disturbing if you were both alive and dead. Unlike quantum mechanics, Einstein’s theory does not address ambiguity explicitly. The great challenge of modern physics is to unite the general theory of relativity with quantum mechanics. This has not yet been done.